Foods packaged as diet foods, ostensibly because they have reduced levels of fat, may not help with weight loss at all. This is because the food-stuff contain high levels of sugar, partly to off-set the reduction in fat.
The problems with so-called diet foods and levels of sugar have been highlighted in a new study from the University of Georgia. Many products marketed as “light” or “low-fat” often contain more sugar than the regular versions, such as low-fat yogurts.
The study used rats, where experiments were run in which rats were fed a diet high in sugar but low in fat. This diet was intended to replicate the ingredients found in many ‘health’ and ‘diet’ foods. These rats were compared with a group red a more nutrient balanced diet.
The experiment, which ran for four weeks, found that the rats given the health food diet saw an increase in body fat mass when compared to the control group. In addition the high levels of sugar found in the diet foods lead to ill-health issues with the rats, such as liver damage and brain inflammation. This is based on various measures being taken from the rats, such as body weight, calorie intake, overall body composition and fecal samples. The fecal samples allowed for the microbial content to be assessed.
Commenting on the research, lead scientist Professor Krzysztof Czaja, who works at the University of Georgia’s College of Veterinary Medicine, stated: “Most so-called diet products containing low or no fat have an increased amount of sugar.” A major concern is, the researcher discusses, is that these additives are camouflaged under various names which appear designed to obfuscate what the actual ingredients are and, possibly, give the impression that these extra ingredients are healthy.
The researcher draws out another important finding from the study, in relation to calorific intake. Here Professor Czaja explains: “What’s really troubling in our findings is that the rats consuming high-sugar, low-fat diets didn’t consume significantly more calories than the rats fed a balanced diet.”
The reason for the body mass gain is due to the sugar diet has a greater efficiency at generating body fat. This means rats consuming the low-fat but high-sugar diet require less than half the number of calories to generate the same amount of body fat.
With body fat a major concern was liver fat accumulation. This is potentially dangerous since the liver accumulating more fat leads to fatty liver disease, which can cause long-term liver damage. The use of brain inflammation means that communication between the gut and the brain becomes faulty, and this affects the signal from the gut to the brain, via the vagus nerve, to determine when the stomach is full.
The researchers point out that although the study is with rats, the effects may well translate to people. Further study is needed to assess this.
The study has been reported to the journal Physiology & Behavior. The paper is titled “Diet-driven microbiota dysbiosis is associated with vagal remodeling and obesity.”